help me with K8s setup

Need to configure my existing Spring Boot app with K8s on Google Cloud. Currently the pods can't access the managed Postgres instance.

I'm an engineer myself, but I need help with infrastructure and Google Cloud. I already have a Spring Boot app which I'm trying to get deployed to GKE. Currently, my pods that need data access cannot reach the Google Cloud managed Postgres. I need someone that will help me set this up.

I would do a screen share and walk through I have so far. I'm hoping they can tell me where I went wrong with the setup.